I claimed the whole Cyclotaur Maze and some time later I got message that I've been attacked... but there was no enemy there. This attack actually was made by my Rouge on Hydraulic Pad, Pipe and than later Cannon (which wasn't claimed because the obvious collision) placed in Cyclotaur Maze. It's like that Hydraulic Pad belongs to me because a tile below it was claimed (Cannon didn't shoot my creatures), but still my Rogue managed to destroy them.

Moreover, like in previous case of bridges, "claimed" hydraulics cannot be sold. Maybe because they're still might be considered as a hostile to the game?